By Huw Jones LONDON (Reuters) – Britain, rattled by the recent near meltdown of some pension funds, is pressing ahead to tighten oversight of the so-called shadow banking sector, taking the lead ahead of possible co-ordinated international action. UK regulators could preempt recommendations by the G20’s Financial Stability Board (FSB) to require permanently higher liquidity buffers for Liability Driven Investment (LDI) funds – used by UK defined benefit pension schemes – backed by regular stress tests, two sources said. The Bank of England in September had to buy UK government bonds after the …