Aug. 21 (Bloomberg) -- Peter Mandelson, the U.K. business secretary and the senior member of Gordon Brown’s government, was hospitalized today for what his office described as a routine operation on his prostate.

The 55-year-old Mandelson, named “first secretary of state” by Brown in June, is expected to stay overnight in St. Mary’s Hospital in London, according to a statement from his office. The operation had been long-planned and was for a benign condition, the statement said.

It’s the second time in less than a year that Mandelson has been admitted to the hospital. In October, just after Brown brought him back into the British government from his job as European Union trade commissioner, he was rushed to St. Mary’s for a kidney-stone operation.

Mandelson, who quit the House of Commons in 2004 to take up his EU post, was appointed to the upper, unelected House of Lords to enable him to rejoin the government and is known as Lord Mandelson. First secretary is an honorific title that carries no formal responsibilities. It was last held by John Prescott, who was deputy prime minister under Tony Blair.

In the past few weeks, journalists have asked Mandelson several times whether he was interested in succeeding Brown as Labour Party leader, after the government announced legislation that would allow appointed lords to renounce their peerages and stand for the Commons. Bookmaker Ladbrokes Plc has him as sixth favorite to succeed Brown.

St. Mary’s Hospital today referred enquiries to the Department for Business.

Prostate Conditions

The prostate, which is a walnut-sized gland that forms part of the male reproductive system, is located just below the bladder, where urine is stored, and surrounds the urethra, where urine passes from the body.

During puberty, a man’s prostate doubles in size. The gland starts to grow again at around age 25, and years later the growth can pressure the urethra, causing frequent urination and limiting the bladder’s ability to empty completely.

The condition, known as benign prostatic hyperplasia or BPH, develops in about half of men in their sixties and as many as 90 percent of those in their seventies and eighties, studies show.

Prostate cancer was the most common malignancy in U.S. men last year with 186,320 new cases, and the second-highest killer among cancers with 28,660 deaths, according to the American Cancer Society in Atlanta. More than 55 percent of men who are 50 or older undergo an annual blood test for the disease.

To contact the reporter on this story: Robert Hutton in London at rhutton1@bloomberg.net

Last Updated: August 21, 2009 05:00 EDT