Sept. 19 (Bloomberg) -- U.K. property companies led by Land Securities Group Plc and British Land Co. climbed the most in almost 23 years in London after the U.K. and U.S. stepped up efforts to ease the credit-market seizure.

The FTSE 350 Real Estate Index rose as much as 15 percent, the most since the index started at the beginning of 1986. It was 5.3 percent higher at 9:55 a.m. in London, paring this year's decline to 16 percent.

``It has to come down to the action that is happening on both sides of the Atlantic,'' said John Perry, a property analyst at Deutsche Bank AG in London. ``Real estate preceded the broader market on the way down and from a fundamental standpoint, it was closer to the bottom than other industries.''

The U.K.'s Financial Services Authority and the Securities and Exchange Commission are banning speculators from betting against financial shares. U.S. Treasury Secretary Henry Paulson and Federal Reserve Chairman Ben S. Bernanke want to remove devalued mortgage-linked assets from American financial companies' balance sheets.

Short sellers try to profit by betting stock prices will fall. In a short sale, traders borrow shares from their broker that they then sell. If the price drops, they buy back the stock, return it to their broker and pocket the difference.

Lack of Credit

The lack of credit, coupled with a slowing global economy, has caused the value of shops and offices to slump. Offices in London's main financial district have fallen 27 percent since July 2007.

Land Securities, the U.K.'s largest real-estate investment company by market value, climbed 81 pence, or 6.7 percent, to 1,298 pence. British Land Co., London's largest office landlord, gained 32.5 pence, or 4.5 percent, to 759 pence. Perry has a ``buy'' rating on British Land and a ``hold'' recommendation on Land Securities.

Minerva, the London-based property developer that received an offer from a Dubai company in July, rose 16 pence, or 20 percent, to 94.75 pence. It was the second-biggest gainer in the 308-company FTSE Small-Cap Index.

To contact the reporter on this story: Peter Woodifield in Edinburgh at pwoodifield@bloomberg.net.

Last Updated: September 19, 2008 05:31 EDT