Lloyds Banking Group CEO Antonio Horta-Osorio said he would focus more on strategy and less on day-to-day issues when he returns to work in January after being forced to take a two-month break because of exhaustion.

Horta-Osorio, 47, said he was still taking mild doses of a treatment for insomnia, blaming sleep deprivation for the illness that sidelined him eight months after he took on the top job at the bank.

He said he had spent a week resting in the care of the Priory clinic, a private medical group that treats wealthy clients for stress-related conditions and also looks after celebrities entering rehab.

At the beginning of September, I started to have problems sleeping, he told London's Evening Standard newspaper.

I'd go to bed exhausted but could not sleep. I could not switch off. I was ending up with just two or three hours' sleep every night, he added.

Horta-Osorio said he then sought medical advice from a specialist.

He told me my battery was in effect so run down it was virtually on zero. I went to the Priory clinic for a week to rest. Then I went home and was immediately sleeping eight hours a day, he added.

The treatment involved medicine to help me sleep. I'm still on mild doses of that, which I expect to come off in the next few weeks.

Lloyds, 40 percent owned by the government after a bailout in 2008, said on Wednesday that it would give other members of the senior management team more responsibility to help reduce the stress on its leader.

I don't believe I have been damaged by this, he said. I'm not going to work any less -- just differently, by detaching myself from Lloyds' day-to-day running and focusing on strategy.

(Reporting by Keith Weir; Editing by Will Waterman)