Germany's KfW KFW.UL has approached investment banks about the sale of at least part of its stake in Deutsche Post DHL (DPWGn.DE), which has a market value of 4.9 billion euros ($6.2 billion), three people familiar with the process said.

The state-controlled development bank "is sounding out the market," an investment banker familiar with the deal told Reuters on Friday, while another of the people said: "Asian investors would make sense from a strategic point of view."

KfW has contacted investment banks this week about the possible sale, the sources said, adding no bank has been formally mandated yet.

Deutsche Post, KfW and Germany's finance ministry declined to comment.

Deutsche Post generates about 14 percent of annual sales in Asia and its DHL business is market leader in the express delivery market there, ahead of U.S. rivals FedEx (FDX.N) and United Parcel Service (UPS.N).

Germany holds 30.5 percent, or 368 million shares, in Deutsche Post, Europe's biggest express delivery and mail company, via KfW.

Of that, about 54 million shares - worth about 720 million euros - are locked up in a convertible bond that was issued by KfW in 2009 and matures on July 31, 2014.

One person said the German government had not yet decided whether to sell a stake in Deutsche Post and would only do so if it could fetch a higher price than the value at which the stake is held in KfW's books.

Shares in Deutsche Post have gained almost 50 percent since reaching a low of 8.90 euros in September. But they still trade more than a third below the 21 euros at which the stock was issued when Deutsche Post floated in 2000.

STATE HOLDINGS

Germany's economy ministry said late last year it would examine the possibility of exiting its holdings in Deutsche Post as well as former state monopoly Deutsche Telekom (DTEGn.DE), of which it owns about 17 percent via KfW.

Financial sources said the German government had no plans to fully exit its holding in Deutsche Telekom at the moment.

Germany, which also owns a 25 percent stake in the country's second-biggest bank Commerzbank (CBKG.DE), had targeted billions of euros of proceeds from privatizations this year.

The FDP, the junior partners in Chancellor Angela Merkel's centre-right coalition, in particular campaign for "private before state", and the government as a whole is keen to consolidate public finances amid the euro zone's sovereign debt crisis.

So far, Berlin has begun the privatization of real estate companies TLG Immobilien and its subsidiary TLG Wohnen.

Deutsche Post has also previously signaled that further privatization steps would be welcome. It has been rumored to be considering a secondary stock market listing in Asia, but its finance chief Larry Rosen said last month there were no current plans for such a move.

But any large deal could leave Deutsche Post without an anchor investor to prevent a breakup of its mail and DHL businesses, after Dutch rival TNT was forced to dismantle itself.

TNT was the first European mail operator to be privatized in 1989. Last year, it was split into mail business PostNL (PTNL.AS) and express company TNT Express (TNTE.AS), which was bought by UPS this year.

One way to avoid a carve-up would be to sell a stake to a strong long-term investor such as a sovereign wealth fund, limiting the number of shares freely traded on the market.