* Graphic: World FX rates in 2020 http://tmsnrt.rs/2egbfVh

* Graphic: Trade-weighted sterling since Brexit vote http://tmsnrt.rs/2hwV9Hv

LONDON, April 6 (Reuters) - Sterling slipped on Tuesday and was on track for its worst day against the euro in five weeks as investors took some cash off the table, while continuing to bet on a speedy re-opening of the British economy.

Expectations of a UK economic rebound, spurred by a rapid COVID-19 vaccination program, have just helped sterling to record its best quarter since 2015 versus the single currency.

But as traders returned from the long Easter weekend, the pound fell as much as 0.7% to 85.51 pence versus the euro at 1440 GMT, putting it on track for its worst session since Feb. 25.

Sterling also fell 0.5% against the dollar to $1.3844, after earlier touching $1.3919, its highest since March 19.

"It is the re-opening of London this morning that is seeing sterling under some initial pressure, as sellers have returned and taken advantage of the rally seen over the last 24 hours or so," said Stuart Cole, chief macro strategist at Equiti Capital in London.

Cole added the selling appeared to be a mixture of profit-taking and new short positions being initiated.

On Monday, the pound recorded its best day against a weakening dollar since Feb. 18, as U.S. Treasury yields held below recent highs. Low liquidity, with many parts of the world off for the Easter break, was seen exaggerating moves.

Market participants continued to expect further gains for the pound in the months ahead.

With the vaccine program rolling out rapidly across Britain and infection numbers falling, Prime Minister Boris Johnson confirmed on Monday a planned re-opening of the economy would take place next week.

Shops, gyms, hairdressers and outdoor hospitality areas in England will re-open. The government is also looking at a COVID-status certification system, or vaccine passport, to help re-open larger events.

Britain will begin the rollout of Moderna's COVID-19 vaccine in mid-April, vaccine deployment minister Nadhim Zahawi said on Tuesday, adding the inoculation program was on track to meet government targets.

Some 12 million second doses are planned to be distributed in April.

Johnson also said on Monday his government hoped non-essential international travel would resume from May 17.

(Reporting by Joice Alves; Editing by Larry King and Mark Potter)